1. Field of the Invention
The present invention relates to a packaging system for packaging articles in flexible, bag-like containers, and more particularly to the use of a packaging apparatus having a novel and improved support for absorbing stresses which would otherwise be imposed on the container by the impact of the articles being dropped into the container during loading.
2. Prior Art
Each of the referenced patents describes the utilization of a plastic web composed of a chain of interconnected bags. The bags are each open on one face while the other face of each bag is connected to a contiguous bag along a line of weakness.
A simple mechanism for using a web of bags in packaging is described in the Article Patent. A coiled web is positioned on a mandrel in a carton. A blower is coupled to the carton to provide a positive pressure within the carton. Bags are fed, closed end first, through a slot in the carton. As the bags emerge from the carton they are inflated by a flow of air emitted from the slot due to the positive pressure in the carton. A product is inserted in the inflated bag. The operator then moves the web until the next bag emerges from the box and inflates, and separates the loaded bag for a sealing operation.
In the Machine Patent, a machine is described and claimed which dispenses the bags, seals them and then severs them in sequential, automatic operations. In addition, the machine is adapted to be connected to automatic counting and conveying equipment so that the products being packaged are all automatically measured and deposited in the bags as the bags are fed to a load station.
In the past, a commonly-used system for dispensing, separating and sealing packages has been basically manual. For these basically manual operations, a machine similar in appearance to that shown in the Machine Patent has been the most widely used. With this commercially-successful arrangement, a web of bags is mounted on a mandrel within a housing. The web is fed through an exit slot near the top of the housing and then downwardly until an open bag is at a load station near the top of the machine and near the exit slot.
In use, the operator deposits the product to be packaged in the open bag at the load station. The operator then grasps the loaded bag, pulling it downwardly until the next bag is at the load station. The loaded bag is then manually severed and the open end is inserted between the jaws of a heat sealer provided near the base of the housing. The jaws are then actuated to close and effect a sealing of the bag. After a predetermined time interval, when a seal has been effected, the jaws will open, allowing the bag to drop in a box or other receptacle beneath the machine.
With the device of the Machine Patent there is a limitation as to the length of a bag which can be handled in that sealing and severing are performed at stations below the load station and along a path of web travel. In addition, while the described machine is quite satisfactory for many applications, the machine does not afford flexibility of optional, often efficient, semi-automatic operation. Neither does it permit the feeding of the web until both the loading and the sealing steps of a cycle have been completed.
The Automatic Machine Patent provided advantages over the prior Machine Patent which included a construction in which the sealing of a loaded bag was effected concurrently with the feed of the next bag. This was accomplished by laterally offsetting the heat-sealing operation from the path of travel of the web into the loading station. The Automatic Machine had other advantages which are described in greater detail in the Automatic Machine Patent. One disadvantage of the Automatic Machine Patent was that in reducing the cycle time by effecting concurrent sealing and feeding, the advantages of the Machine Patent in assuring registration of the two faces of a loaded bag was lost.
When one loads a bag which has one face open and the other face connected by a line of weakness to a web, the expansion of the bag occasioned by the presence of the contents, and the distortions caused by the stresses of the weight of the contents, cause the disconnected face to become malaligned with the connected face. Loading a connected bag may also cause some premature partial severing of the connected face from the web. This distortion and partial severing causes a malalignment which is described in detail in the Machine Patent and which was solved in the Machine Patent. Prior to the present invention one had, then, the option of sealing with concurrent feed or automatic registration of the two faces of a loaded container, but not both.
Various types of bag supports have been provided in the past to support a bag at a load station. Simple shelves were used, for example, in connection with the basically manual system described above. The Article Patent and the Machine Patent each show systems for supporting a bag as it is loaded. Reciprocally movable shelves have been proposed for machines of the Automatic Machine Patent. These supports are illustrative of the many types of supports which have been provided, many of which, prior to the present invention, were not susceptible for use with the device of the Automatic Machine Patent because in one way or another they would interfere with the preferred and described method of operating that machine. That is, they would prevent concurrent sealing and web feeding or they would interfere with one or more of the operations such as by remaining in the path of a loaded container. While a movable support might overcome the interference problem, nothing has been proposed which would afford support for the container as it is being loaded, concurrent feeding and sealing as is taught in the Automatic Machine Patent, and assured registration of the faces of a loaded bag prior to the commencement of the sealing operation.